JavaScript FileMaker T-Shirt Mockup

I need a lightweight FileMaker solution, enhanced with embedded JavaScript, that lets users create on-screen t-shirt mock-ups in a few simple steps. The core requirements are:

• Real-time color customization of the garment.
• Drag-and-drop or click-to-select image upload so customers can place their own artwork on the shirt.
• A set of predefined layout templates the user can cycle through before saving the mock-up.

The file must open seamlessly on Windows and macOS desktops and remain fully functional through WebDirect so staff can demo it in any modern browser. Please keep the code self-contained (no paid plug-ins) and comment it clearly so I can tweak palette options or swap in new shirt silhouettes later.

Deliverables:
1. A ready-to-deploy .fmp12 file with the JavaScript and CSS bundled.
2. Brief setup notes and a one-page user guide showing how to add template images or change default colors.
3. A sample record containing at least one finished mock-up to confirm everything renders the same on desktop and web.

I’ll test on FileMaker Pro 19 and WebDirect before sign-off. If this sounds straightforward to you, let’s get started!

Here is one that is available on GitHub https://github.com/konvajs/konva